Adjustment of aeroplane ailerons



July 22, 1930; c. PALLAVICINO ,7

ADJUSTMENT OF AEROPLANE AILERONS Filed April 6, 1929 Ll/ewfar I Patented July 22, 1930 cEsAnnrALLAvIoINaor- MILAN, ITALY, .a'ssrenoa TO SOCIETAIITALIANAV ERNESTO BREDA'IEER GOSTRUZIONI MECCANICHE, OF MILAN, I TALY v v AnJusrME wr or AEROPLANE Air an Application fiIed APriI 6, 1929ISeilalNo. 353,047, and in Italy October 11, 1928..

,Inthose' aeroplanes in which movable aileron'sare. employed to obtain lateral control of the line of flight, the controls by means'of which the position of the said ailerons is regulated are ordinarily made and arranged in such a way as to render it impossible for one aileron tomove in one direction unless the other moves synchronously and symmetrical-1 ly in the opposite direction. The defect of this arrangement is that it interferes with the manoeuvre and renders it impossible to emcute special evolutions that in certain circumstances would be opportune. V

A type of control has been proposed that would render the displacement of the ailerons, which form acouple, asymmetrical by means of the use of connecting rods arranged. on the ailerons at angles other than right angles; the proportion of the differential displacements thus obtaned being, however, always fixed and invariable.

The present invention has for its objecta: new arrangement whereby the movements-of the ailerons forming a couple are rendered independent of one another, although allowing them to be engaged with one another at will so that the whole of the desired variations in the proportions. between-their displace ments can be obta1ned,.by means of simple operations which can-be efliectedeven during flight. The essentialcharacteristic of this new arrangement isthat each of the ailerons .forming a couple is connected in a manner which varies according'to requirements, with tive to the other'ail-eron of the/same couple,

the connections being formed in such a way as to allow the amplitude andthe direction of one aileron as regards the amplitude and thedirection of the other, as well as the position of the same in respect to the middle position of the said control stick, to be changed at will.

This new arrangement permits new and important possibilities of manoeuvre. In fact,

in case of breakage of any one of the control transmissions, the lateralcontrol of the aeroplane can be maintained the same by means of said arrangement because oneof the two aileport and' starboard, forming a couple, are

rons is always available. On the otherhand,

the arrangement itself allows the pilot 'to modify at will the relative positions of the,

ailerons; it is-possible, for example, to depress both'ailerons Without losing lateral controlof the aeroplane, in such a Way as. to confer greater buoyancy on the'body. This is especiallyuset'ul in certain conditions of flight as well as during the operation of landing. Moreover, it is easy to establish the 0011 nections in such a waythat the movement of elevation ofone aileron will be greater than themovement of depress on or the other;

this being most useful in piloting theaeroplane because the use or the tail planes is rendered-less necessary. The proportion 0r ratio betweenthe angle of elevation and that of depression is greater proportionally to the degree of depression given to both ailerons, which is .most usefullbecause'the potentiality of lateral controlincreases when the speed of the aeroplane is low, that is to say, whenthe "need for lateral control is greatest.

' The attached drawing gives a front View I outline, ofthe central part corresponding to the cockpit, which represents one way of realizing pract-i'callythe present invention. It is given as an example. r

. In the construction shown, the two ailerons,

connected'with the control stick 1 by means of. flexible'cable transmission. These cables 'are guided by'suitable' pulleys and form two separate devices, each consisting of'an 0utward cableand a return cable'- These two de vices are carried: by' two pulleys or levers 2 respectively which are arranged ata 1 suitable distance on both "sides of the control stick 1 and which canbe rotated by means ofthe' crariksyK-fi respectively, which are rigidly fixed tosaid pulleys, and of-the connecting rods l4 which latter can be turned respectively by their pivoted extremities '5-5 on a suitable plate 7 carried by the mov able controlstick. The pivotsj5 5j canbe placed at diilerent and variable .f'p'oints In'order that-the operation of displacing" the pivots may be eilectedeasily; even dur;,

ing flightfmany different methods'of' coir fob nection can be used. Each of these may prove to be more or less suitable according to the case and the results which it is desired to obtain. For example, the pivots 5-5 may be rigidly connected with two wing nuts, lodged in a horizontal box (not shown) arranged on the plate 7 and furnished with slits such as to allow the passage of the pivots themselves, the said wing nuts being screwed on a rod having a right and left hand thread mounted axially in the box it self in such a way that it can rotate in said 7 box, by means of any type of external control.

If the various'parts 01' the transmission connections are proportioned and arranged in such a way that, when the control stick is in the middle position, the pivots 5-5 both coincide in point 6 of the plate 7, on ro tating the control stick the two controls, starboard and port, go through the same move ment and the ailerons forming a couple make synchronous and symmetrical rotations. If the two pivots are then displaced outwardly, the two ailerons assume a downwardly inclined position; and when the control stick is rotated, synchronous and opposite but no longer equal, rotations of the ailerons themselves are produced.

It instead, the two transmissions are adjusted in such a way that by keeping the two pivots 5-5' at a suitable distance apart, the ailerons forming a couple are in a horizontal position, then when the control stick is rotated disymmetrical or differential rotations of the ailerons themselves are produced. If the pivots be kept at a still greater distance apart, the depression of the two ailerons forming a couple is produced, in which case rotation of the control stick produces inverse rotations of the ailerons themselves, the amplitude of which rotations is still more differentiated, the differentiation increasing with the increase in the reciprocal distance between the two pivots. Inverse effects are produced by lessening the distance between the pivots.

The arrangement here described evidently allows the operation of displacement of the connection to be effected in any position whatsoever of the control stick, and also during flight. Analogous results could also be obtained by making the position of the pivots of the pulleys 22' variable, in any suitable way and which technicians know well. The structure of the transmission devices for the controls, their arrangement and their method of attachment to the control stick, may be varied; but such variation is clearly within the scope of this invention.

What I claim is:

A, system of control for the couple-forming ailerons of an aeroplane, comprising a pivoted control stick; an endless cable'associated with each aileron and connected to actuate the same, said cables being disposed at opposite sides of said stick; oppositelyarranged pairs of pulleys whereon the cables are mounted, one pair located adjacent the control stick; a crank secured to the axle of each pulley of said pair; a plate secured to said stick to move therewith; and a pair of oppositely-arranged rods adjustably pivoted at their inner ends to said plate at different points thereon, and at their outer ends to said cranks, thereby to enable variations at will in the amplitude and direction of the displacements of one aileron with relation to those of the other aileron, as well as their position corresponding to the central position of the control stick.

In testimony whereof I afiix my signature.

CESARE PALLAVICINO. 

